Method and apparatus for cleaning radiator tubes and the like



A. R. RUTH D APPARATUS FOR CLEANING Sept. 29, 1953 METHOD AN RADIATOR TUBES AND THE LIKE 3 Sheets-Sheet 1 Filed May 2, 1947 [NVENTOE A. E. RUTH- 3 Sheets-Sheet 2 RUTH A. E 90TH MMAXQ Sept. 29, 1953 METHOD AND APPARATUS FOR CLEANING RADIATOR TUBES AND THE LIKE Filed May 2, 1947 F/g. Z

Sept. 29, 1953 R RUTH 2,653,420

METHOD AND APPARATUS FOR CLEANING RADIATOR TUBES AND THE LIKE Filed May 2, 1947 3 Sheets-$heet 3 AR. RUTH BYQH, e

Patented Sept. 29, 1953 METHOD AND APPARATUS FOR CLEMG' RADIATOR TUBES AND Acquilla a. alumni}; Pic

Application Mug,

This invention relates to th egcleanihg' 'otraili ators and the like and more particularly-lama: method of, and apparatus forI rempving .scale capable or'imparting heat thereto at a. rate such rust, sediment and other foreigntmatteriroin. the interior of thin walled circulation passages such as those of the radiator or an- 'auton iqbile" cooling system. c The internal coating collected inr time uppn foreign matter that would pass freely"throu'gh r.:' ,2 I I eminence radiator. "The fluid is heated between the pump and radiator by an apparatus that' the ifiuid at maximum delivery will reach 5 "thfgradiatdrat or near its boiling point. It will gb'vious that where delivery is restricted and :the' pressure. rises, -much' higher temperatures .result 'iapproitiniately 350 F. at pounds). the inner surface or such p'assages'materially wherethe;scale and consequentconstriction is reduces the efliciency of the radiator and 'inmany *f slight;iand-;the,;flow ratehlgh the solvent and cases will either completely clog a tube-Oreo: abrasive actio nds iincreased and the scale is reduce its diameter at points that the fflow'is f rapidly removed particularly since the temperavery slight and is easily checked by' arnbient turjbrathe fliiidorth'e solution will cause expansion'ot th' tube resulting in its separation a clean tube. This deposit'or scale is ami 1 mm the scale; which, as'hereinbefore noted has brittle skin composed mainlyof calcium. mag-1 ne'sium, and silicates mingled with oxides of the metals forming the cooling system. In an auto"- p creases the pressure and the slower passage ZQ-through'the heater causes the fluid to enter the in thickness progressively toward thebottom of the'tubes and often absent near the lower ends mobile radiator the deposit is heaviest at the upper or entrance ends of the tubes decreasing thereof; It is formed at temperatures rarely ex-Q ceeding 180 and on an average much lower.

While soluble by certain chemicals having little gitis soon broken away at this point.

or no effect on the materials of the circulation system, removal of the deposits by a static or even a circulated chemical solution is a lengthy and uncertain process and in the only practical method using such a solution, with which I am familiar involves in many cases the removal of one header or theradiator and displacement of the scale by forcing a rod through the clogged tubes, a procedure that obviously will often damage the tubes. Furthermore such procedure will not remove scale but merely forms an opening therethrough.

I In accordance with my invention I utilizethe difierence in these deposits and the thin metal walls'of the passage (the coefficient of expansion of scale is roughly estimated as about /5 that of steel and that of brass, the materials from which radiator tubes are most commonlyforined) as an important factor in removing the scale. An aqueous solution of a solvent suchfas V oxalic a'iid'containing a finely divided abrasive isrirculated through the tubes, at a temperature 'dependenton the speed of its delivery from heen iorniedIat much lower temperatures.

lathe-case ofbadly obstructed tubes the effort ot, thepump-to deliver its normal output intubes at much higher temperatures and the extentof separation .or the tube and scale is greater, allowing the solution and its suspended iabrasivetd more readily attack-the scale. Since the tubes and rising as the speed of delivery the scale is initially attacked at its weakest point Scale particles "are notremoved from the solution but broken .down and "retained therein as 'added abrasive. "'This'breakdown is attained partially through attrition, throu h impact in the pump, which is p'reierablyoi t centrifugal typeand through'im'pa'ct again the scale remaining on the walls of'the tube." Obviously the expansion separationmay be acceleratedby heat insulating the radiator during .the cleaning operation.

The above 'processcan be carried out by a very compact apparatus which may be readily and cheaply-produced and which is so easily operated and so nearly automatic in its operation that labor costs are kept at a minimum. Such an apparatus is illustrated in the accompanying drawings wherein:

Figure 1 is a side elevation of the apparatus; Figure 2 is a front elevation thereof, and Figure 3 is a diagrammatic illustration of the circulation system provided by the apparatus.

Referring now more particularly to the drawings, the numeral 10 designatesa support preferably mounted upon. casters I] and of light but rigid construction. Mounted upon thissupport are a solution tank l2, a'motor driven centrifugal pump It, a solution heater I4, and a drain tray IS, the latter in turn mounting supports it for the reception of the lower end of the radiator R which is to be cleaned.

Tank 12 is preferably of the semi-sealed type and has inlets l1, l6, and I9, comprising respectively a filling inlet, an inlet for receiving the main discharge from radiator R, and an inlet for receiving liquid from tray I5. It is further provided with a discharge pipe 20 communicating with the inlet of pump I 3. All of inlets l1, l8, and I9 are in the form of tubes having their lower ends opening into the tank below the liquid level maintained therein during cleaning operations whereby to avoid excessive foaming of the treating solution.

Pump I3 is, as previously noted, a centrifugal pump and is of that type of centrifugal generally known as a s1ip pump i. e. a pump which when confronted with a given head simply churns the pumped fluid passing only enough thereof to maintain such pressure. Practically it should alsohave the characteristics of the ordinary centrifugal sand pump having impeller blades capable of withstanding not only the erosive action of the abrasive contained in the circulated solution but likewise the impact and erosion of scale particles separated from the tubes during the cleaning operation. A pump of this type capable of delivering 42 gallons of the cleaning solution per minute and of developing l5 pounds gauge pressure as a maximum is ordinarily satisfactory for use with standard radiators of automobile or truck cooling systems. Reduction of the amount of fluid delivered by the pump may of course be effected by a valve 2| arranged in the intake connection 26.

Heater l4 may be of any suitable type a gas heater being at present shown. The capacity of this heater must be such that when the maximum amount of the cleaning fluid is being delivered through connection 22 the fluid is maintained at or about its boiling point. The heater should also be arranged to eliminate heat losses and to this end the connections 22 to the radiator R is'made as short as possible. In the connection 22 I provide a thermometer 23 and a pressure gauge 24 for purposes presently to appear.

Tray l5 functions as a support for the radiator Rand as a means for returning to tank l2 any leakage from radiator R and discharge from the overflow pipe (not shown) with which suchradiators are usually provided. It is arranged above tank l2 and at the greatest convenient height to insure the maximum possible head pressure against pump l3. Supports l6 may be wooden bars notched at 25 to receive the tray walls and form a seat receiving the lower header 26 of the radiator R. Flexible connections 21 and 28 are used to connect the connection 22 and inlet i8 of tank l2 to the lower and upper headers 26 and 29 of the radiator.

Support l includes a suitable means for maintaining radiator R in a vertical position. In the present instance the framework of the support is shown as including vertical members 36 projecting upwardly at opposite sides of tray l and having adjacent their upper ends a brace 3| and flexible element 32 for confining the radiator R. A heat insulating jacket 33 of any suitable construction is provided for shielding the radiator from the ambient atmosphere. An outlet valve 34 is in connection 22 for the connection of a branch tubing 35 to enable use of the system in other cleaning operations. Support l0 may include a tray 36 for the reception of accessories.

In use of apparatus of this character the tank I2 is charged with the desired amount of the solution, for example, one containing (one pound) of oxalic acid and 1b. (one-third pound) of brick dust or similar abrasive. The radiator is placed on tray l5, connected to the connection 22 and inlet I8 of tank I 2, jacketed, and secured to braces 3|. Pump I3 is then started and heater l4 placed in operation. If the tubes T of the radiator are badly clogged this will be indicated by pressure and temperature rises in the connection 22. As the tubes T clear the pressure will drop and when the known low pressure-is read on gauge 24 the radiator is clean. Continuing circulation for a short time will scour and polish the tubes surfaces. It will be seen that no skill is necessary to operation and that constant attendance is unnecessary, an occasional inspection of the thermometer and gauge being sufficient.

Since both the method and apparatus are capable of modification without departing from the spirit of my invention I do not wish to be understood as limiting myself to those described except as hereinafter claimed.

I claim:

1. The method of removing deposits of scale and the like from the inner surfaces of thin walled heat transfer circulation passages comprising, making attempted delivery through the passages of an amount of a scale dissolving solution under increased pressure and containing elements contributing to the removal of said deposits equal to the capacity of the passages when clean, and heating the solution between the point where the pressure thereof is increased and the passages at a rate such that said fluid when delivered to the passages at such capacity is approximately at least at its boiling point.

2. The method of removing deposits of scale and the like from the inner surfaces of thin walled heat transfer circulation passages comprising, making attempted delivery throughthe passages of an amount of scale dissolving solution under increased pressure and containing elements contributing to the removal of said deposits equal to the capacity of the passages when clean, inhibiting heat transfer from said passages and heating the solution between the point where the pressure thereof is increased and the passages at least at a rate such that said fluid when delivered to the passages at such capacity is approximately at its boiling point.

3. The method of removing deposits of scale and the like from the inner surfaces of thin walled heat transfer circulation passages comprising, making attempted delivery through the passages of an amount of a scale dissolving solution under increased pressure and containing elements contributing to the removal of said deposits equal to the capacity of the tubes when clean, heating the solution between the point where the pressure thereof is increased and the passages at a rate such that said fluid when delivered at such capacity is approximately at at least its boiling point, and terminating delivery of the solution to the passages when the pressure of the delivered fluid arrives at a predetermined minimum.

4. The method of removing deposits of scale and the like from the inner surfaces of thin walled heat transfer circulation passages comprising, making attempted delivery by pressure creating means of a solution of a solvent of the deposit to the outlet of the passages at a rate equal to the capacity of the passages when clean, limiting the pressure of delivery of the solution to that of predetermined safe rate for the passages, applying heat between said pressure creating means and the point of delivery to the passages to all of the fluid delivered by said means to the passages at a rate such as when the solution is delivered to the passages in amounts approximating the rated capacity of the passages the solution is at least at its approximate boiling point, and terminating delivery of the solution when the pressure of the solution as delivered to the passages is at a, predetermined minimum.

5. Apparatus for cleaning scale deposits and the like from the interiors of motor vehicle radiators having thin walled tubes and inlet and outlet ports arranged respectively near the upper and lower ends of said radiators, said apparatus comprising in combination, a tank adapted to contain a quantity of scale solvent solution, a pump connected to said tank by a conduit, a heater for said solution connected to the inlet end of said pump by a conduit, a jacket arranged to enclose a radiator to be cleaned, a conduit extending between the outlet end of said heater and said jacket and arranged to be connected to one port of said radiator, and another conduit extending between said jacket and said tank, one end of the former conduit being arranged to be connected to the other port of said radiator, whereby upon said pump being operated said apparatus will function to deliver heated solution to said one port of said radiator and upon meeting obstruction to passage within said radiator tubes pressure will be developed within said heater and former conduit and thereby increase the temperature of said solution therein.

6. The apparatus set forth in claim further including a tray adjacent the bottom of said jacket, said radiator being positionable above said tray, and a drain extending from said tray 0 to said tank.

7. The apparatus set forth in claim 5 further including supporting means for a radiator within the lower portion of said jacket and bracing means positioned adjacent said support and operable to hold said radiator upon said support.

8. The apparatus set forth in claim 5 further characterized by said jacket being larger than but conforming generally in shape to a radiator and the major axis of said jacket being arranged vertically when in use, one wall of said jacket being apertured to receive said conduits connectible to said ports of said radiator and frame means engageable with said jacket to support it as aforesaid.

9. The apparatus set forth in claim 8 further characterized by the bottom of said Jacket being open, whereby said jacket may be lowered onto a radiator substantially to enclose it.

ACQUIILA R. RUTH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,121,308 Thomas Dec. 15, 1914 1,507,151 Bennett Sept. 2, 1924 1,628,141 Gray May 10, 1927 1,701,824 Robinson Feb. 12, 1929 1,887,722 Schoener Nov. 15, 1932 1,908,954 Carmin May 16, 1933 1,939,112 Eulberg Dec. 12, 1933 2,018,403 Hussar Oct. 22, 1935 2,222,516 Powell Nov. 19, 1940 2,235,885 Johnson Mar. 25, 1941 2,254,075 Lawson Aug. 26, 1941 2,254,980 Simmons Sept. 2, 1941 2,418,063 Alling Mar. 25, 1947 2,430,976 Dutra Nov. 18, 1947 2,442,272 Jafia May 25, 1948 

